#include<stdio.h>
void main()
{
    float x,y;
    scanf("%f",&x);
    if(x>0){
        if(x<=10){
            y = x-5;
        }
        else{
            y = x-10;
        }
    }
    else{
        if(x<=-10){
            y = x+10;
        }
        else{
            y = x+5;
        }
    }
    printf("y = %f\n",y);
}